Power operated hole digger



Aprifl 33, 1957 T F, HE 3,313,363

POWER OPERATED HOLE DIGGER Filed March 2, 1965 United States Patent Gfifice 3,3 E3353 Patented Apr. ll, 1967 3,313,363 PO VER GPERATED HULE BIGGER Thomas F. Henehry, Hawleyviile Road, Eethel, Conn. 363% Fiied Mar. 2, 1965, Ser. No. 436,562 Ciairns. (Cl. 175-2il7) This invention relates in general to a hole digger, and more specifically to a power operated hole digger.

Heretofore, a great difficulty had been encountered digging a hole into the ground, as for example, a hole for receiving a fence post, or an underground conduit, pipe or the like. In many instances, it is frequently required to dig a hole in the earth which has been covered with a layer of concrete, as for example, in the fioor of a cellar of a building structure or the like to bring into the building an extra water pipe, cable or such. Many times it is also necessary to dig a hole in the ground which may be paved as in the case of a street or a sidewalk. In such instance it was heretofore necessary to first break through the relatively hard surface of concrete or paving with a pick or pneumatic hammer or the like to reach the ground or earth therebeneath, and thereafter excavate the earth by digging with conventional shoveling means. In so doing, much more concrete and/or paving and earth is generally excavated then is otherwise necessary in forming a hole to accommodate or receive such things as a fence post, a water pipe, cable or the like. For this reason, much time, effort and expense was heretofore expended to dig a hole by conventional pick and shovel means for such items. Also conventional shovel and pick digging of holes presented a removal problem of the excavated earth. Generally, it was customary to cart the earth so excavated away in either a cart, wheelbarrow, or truck or otherwise simply pile the earth adjacent the hole. Thus, the added problem of the earth removal substantially added to the time, effort, and cost in forming or digging such holes. Also more earth than necessary is evacuated, thereby removing the support for the paved or concrete surface. When this occurred, such paved or concrete surface would tend to buckle or crack.

It is therefore an object of this invention to overcome the foregoing disadvantages by providing an earth boring tool in which the dimensions of the hole to be formed can be maintained to substantially the size or dimension of the post or conduit desired to be placed in the hole, thereby minimizing the amount of earth which is required to be excavated.

Still another object is to provide a hole digger in which the loosened earth is automatically removed by entrainment resulting from a suction created by a negative pressure producing source adapted to be utilized in conjunction with the hole digger.

Another object is to provide a readily portable hole digger which can be power operated.

Still another object is to provide an improved power operated hole digger that is relatively light in weight, durable, portable, inexpensive to manufacture, relative simple construction, and positive in operation.

The foregoing objects, and the other features and advantages are attained by a hole digger comprising a housing formed as an elongated tubular member having a relatively long main body portion and angularly disposed upper body portion. The respective housing portions are connected into open communication with one another. Accordingly, the upper end of the housing is adapted to connect to a negative pressure producing source, as for example, a vacuum pump or the like. In the upper end of the housing there is provided an opening which is disposed in substantial axial alignment with the longitudinal axis of the main housing portion with a bearing sleeve connected in axial alignment with the opening. A shaft extending longitudinally of the lower housing portion is extended upwardly through the opening and bearing sleeve, the extended end portion of the shaft being rotatably journaled by a bearing therein. The other end of the shaft has connected thereto a plurality of cutting blades which are specifically constructed and arranged so as to function both as a bearing for the other end of the shaft and as a means for loosening the dirt as the shaft is rotated. Means are provided to prohibit longitudinal displacement of the shaft. Suitable power means may be detachably connected to the extended end of the shaft so as to provide the power necessary for effecting rotation of the shaft and the cutters connected thereto. Thus, in operation, actuation of the cutter effects loosening of the dirt as the vacuum pump effects removal thereof by entrainment of the dirt up through the housing.

A feature of this invention resides in the relative simplicity of construction of the hole digger of the instant invention.

Another feature of the invention resides in the provision of cutting blades constructed and arranged so as to function both as a rotary bearing for one end of the drive shaft and for loosening the ground or dirt.

Another feature of this invention resides in the relatively simple manner in which the drive shaft is rotatably journaled in the housing of the digger.

Still another feature of the invention resides in the provision of utilizing the relatively simple hole digger of the instant invention in conjunction with a negative pressure producing source whereby the removal of the loosened earth is effected by entrainment of the dirt through the tubular housing of the digger.

Other features and advantages will become more readily apparent when considered in view of the drawings andspeci-fication in which:

FIGURE 1 illustrates an elevation view of the hole digger of the instant invention as utilized in conjunction with a power operating means and a negative pressure source for effecting the removal of the earth loosened thereby.

FIGURE 2 is an'enlarged section view of the hole digger of the instant invention with portions thereof broken away.

FIGURE 3 is a detailed sectional view taken along line 33 of FIG. 2.

FIGURE 4 is a plan view taken along line 4-4 of FIG. 3.

FIGURE 5 is a bottom plan view of the digger as viewed along line 55 in FIG. 2.

Referring to the drawings, there is shown therein the hole digger 1t constructed and arranged in accordance with the instant invention, As shown, the hole digger 10 comprises a tubular housing 11 that includes a relatively long elongated lower body portion 11A and an angularly disposed upper end portion 118. The housing 11 may be formed of any suitable tubular material in which the upper end portion 11B may be either bent at a desired angle or suitably joined to the lower body portion 11A by any suitable means, as for example, welding, soldering, brading, friction fit, or the like. As shown in FIG. 2, the main body portion 11A of the housing is disposed in open communication with the upper end portion 11B of the housing. The end of the upper housing portion is constructed and arranged to detachably connect to a flexible conduit 12 which connects to the inlet 13 of negative pressure source 14, as for example, a vacuum pump, or the like. cooperatively associated with the vacuum pump means 14 is a receptacle for receiving the loosened earth as will be hereinafter described.

Referring to FIG. 2, a wall portion of the upper housing portion 11B is provided with an opening 15 which is disposed in substantial axial alignment with the longitudinal axis of the lower housing portion 11A. A hearing sleeve 16 is connected to the upper housing portion 118 in axial alignment with the opening 15 formed therein. The upper end of the bearing sleeve 16 counterbored to provide an internal shoulder to form a bearing seat 17.

A shaft 18 extends longitudinally of the housing 11 with its upper end 18A extended through the opening 15 and a bearing sleeve 16 connected thereto. A suitable bearing 19 is seated on the bearing seat 17 for rotatably journalling the shaft 18 within the sleeve. A clamping plate 20 secured by fasteners 21 retains the bearing 19 in position. The arrangement is such that the bearing 19 for the upper end portion of the shaft is sandwiched between the shoulder 17 and the retaining plate 20.

As shown, the retaining plate 20 is provided wtih a central opening 20A through which the end 18A of the shaft 18 extends. Accordingly, the opening 20A in the bearing plate 20 is provided a clearance therearound.

In order to prohibit longitudinal displacement of the shaft 18 within the housing, the shaft 18 is provided with a pair of pins 22 that extend transversely therethrough. Accordingly, the pins 22 are spaced so that they extend through the shaft 18 at a point immediately above and below the race of the bearing 19. Accordingly, the shaft 18 is prohibited from longitudinal displacement with respect to the bearing 19.

The other end of the shaft 18B is rotatably journaled and maintained in axial alignment within the housing 11 by means of a plurality of cutting blades 23 which are connected thereto. As shown, the cutting blades 23 are substantially L-shaped with the outer edge portions 23A of the vertical leg of the respective cutter blades functioning as a bearing for maintaining the axial alignment of the shaft 18 with respect to the internal wall of the housing.

The horizontal leg portion of the respective cutting blades are provided with cutting edges 23B for biting into the earth during the operation of the tool. If desired, a hardened collar 24 may be connected to the lower end of the tubular housing 11 so as to provide a tough, longer wearing, surface for the cutter blades 23 disposed in bearing relationship therewith.

A suitable power means 25, as for example, a hand held electric motor, e.g., a drill motor, or the like, may be detachably connected to the extended end 18A of the shaft 18. Also, the hole digger 10 may be powered by an air motor.

In operation, it will be noted that energizing of the power source 25 will effect rotation of the shaft and the cutting blades connected thereto. Thus, the cutting edges of the blades bite into the earth, causing the earth to loosen. With the negative pressure source or vacuum 14 operating, the loosened earthen particles are then entrained upwardly through the tubular housing 11 by the suction produced and collected in a suitable receptacle 14A.

With the tool thus described, it will now be readily apparent that a smooth side hole or bore can be formed directly into the earth in a manner in which the size or shape of the hole can be precisely maintained substantially to the size and shape of the post or conduit adapted to be received in the hole. Consequently, a minimum of excavation is all that is necessary with the tool of the instant invention.

It is to be noted that the tool described is particularly adapted for digging holes under a paved or concrete surface. In such instances all that is required is for a hole to be drilled or bored into the concrete or paved surface of a size which is only slightly larger than that of the hole to be formed in the earth therebeneath, With the hole in the hardened surface, so drilled, the hole digger herein described then can be inserted through the hole in the concrete or paving and actuated to remove the earth therebeneath by first loosening of the same by rotation of the cutting blades, and thereafter removing the loosened earth by entrainment resulting from the negative pressure produced by the actuation of the vacuum pump 14 operatively connected to the end of the housing member 11.

From the foregoing, it will be noted that a hole of a size dug beneath the hardened surface can be correctly sized and maintained to substantially the dimension of the article to be received thereby. Accordingly, a heretofore difiicult, if not impossible, task is now expediently performed.

Also, if desired, the instant tool may be used for digging irregularly shaped holes to precise dimensions merely by one working the end of the tool in accordance with the pattern or shape of the hole desired to be formed. By thus working the tool around the outer periphery or outline of the hole to be formed, any shape or size hole can be dug as may be required for any given particular job or situation. With the tool described, excavation can be reduced to a minimum for any given job. Also, the sloping of the sides of the hole, as customarily encountered with conventional digging equipment is now completely eliminated. With the tool described, the sides of the hole can be maintained as smooth and straight as desired.

While the instant invention has been described with reference to a particular embodiment thereof, it will be readily understood that variations and modifications thereof may be made without departing from the spirit or scope of the instant invention. For example, while the instant description is directed to an industrial type hole digger, it will be apparent that the same may be scaled down to a hand-held instrument for use by sculptors or model makers or the like.

What is claimed is:

1. A hole digger comprising:

(a) a tubular housing having an elongated body adapted to connect with a source of negative pressure,

(b) a shaft extending longitudinally of said body, one end of said shaft extending through said opening in said housing,

(c) a bearing for rotatably journalling the end of the shaft extending through said opening,

(d) means for retaining said bearing to said housing,

(e) means for prohibiting longitudinal displacement of said shaft Within said housing,

(f) and a cutter means connected to the other end of said shaft,

(g) said cutter means having cutting edges projecting beyond the end of said housing to loosen the dirt as said shaft and connected cutter means rotate,

(h) and said cutter means including a cutter having a cutting edge portion and a bearing edge portion, said bearing edge portion being disposed in rotatable bearing relationship with the internal surface of the lower end portion of said housing for rotatably journalling the other end of said shaft within said housing, and said cutting edge portion extending beyond the lower end of said housing.

2. A hole digger comprising:

(a) a tubular housing having an elongated lower body portion, and an angularly disposed upper end portion, said body portion and upper end portion being in open communication with one another,

(b) said upper end portion being adapted to connect with a source of negative pressure,

(c) said upper end portion having an opening formed therein which is disposed in substantial axial alignment with the longitudinal axis of said lower body portion,

(d) a bearing sleeve connected to said housing in axial alignment with said opening,

(e) a shaft extending longitudinally of said lower body portion,

(f) one end of said shaft extending through said opening and bearing sleeve connected to said housing, (g) a bearing disposed in said sleeve for rotatably journalling the end of the shaft extending through said sleeve,

(h) means for retaining said bearing in said sleeve,

(i) means for prohibiting longitudinal displacement of said shaft within said housing,

(j) and a cutter means connected to the other end of said shaft,

(k) said cutter means including a blade having a cutting edge projecting beyond the end of said housing to loosen the dirt as said shaft and connected cutter means rotate,

(l) and said blade including a bearing portion for rotatably journalling the other end of said shaft within said housing.

3. A hole digger comprising:

(a) means defining a housing,

(b) said housing means includnig an elongated tubular lower housing portion and connected angularly disposed upper housing portion,

(c) said respective housing portions being in open communication,

((1) said upper housing portion having an opening formed in a wall portion thereof whereby said opening is disposed in substantial axial alignment with the longitudinal axis of said lower housing portion,

(e) a bearing sieeve connected to said upper housing portion in axial alignment with said opening and lower housing portion,

(f) a shaft extending longitudinally of said lower housing portion, one end of said shaft extending through said opening and bearing sleeve,

(g) a bearing disposed in said sleeve for rotatably journalling the end of said shaft extending therethrough in said sleeve,

(h) means for retaining said bearing in said sleeve,

(i) means for prohibiting longitudinal displacement of said shaft relative to said bearing,

(j) means rotatably journalling the other end of said shaft adjacent the lower end of said lower housing portion,

(k) said latter means including a plurality of cutting blades connected to the end of said shaft,

(1) and said blades having a bearing edge portion in bearing relationship with the end of said housing.

A hole digger comprising:

(a) means defining a housing,

(b) said housing means including an elongated tubular lower housing portion and connected angularly disposed upper housing portion,

(c) said respective housing portions being in open communication,

(d) a vacuum producing means connected to the end of said upper housing portion,

(e) said upper housing portion having an opening formed in a wall portion thereof whereby said opening is disposed in substantial axial alignment with the longitudinal axial alignment with the longitudinal axis of said lower housing portion,

(f) a bearing sleeve connected to said upper housing portion in axial alignment with said opening and said lower housing portion,

(g) said bearing sleeve being formed with an internal shoulder spaced from the upper end thereof,

(h) a shaft extending longitudinally of said lower housing portion, one end of said shaft extending through said opening and bearing sleeve,

(1) a bearing seated on said shoulder for rotatably journalling the end of said shaft extending therethrough in said sleeve,

(j) a bearing plate secured to the end of said sleeve to retain said bearing between said shoulder and said plate,

(k) a pair of spaced pins extending transversely through said shaft, said pins being disposed on either side of said bearing to prohibit longitudinal displacement of said shaft relative to said bearing,

(l) means rotatably journalling the other end of said shaft adjacent the lower end of said lower housing portion,

(In) said latter means including a plurality of L-shaped cutting blades connected to the end of said shaft, (n) said blades having the vertical leg portion thereof in bearing relationship to the housing, and having the horizontal leg portion projecting beyond the end of the housing,

(0) and means connected to the extended end of said shaft to effect the drive thereof whereby the rotation of said cutters effected the loosening of the ground and whereby said loosened ground is removed by entrainment thereof upwardly through said housing.

5. The invention as defined in claim 4 and including a collar of hardened material connected to the end of said lower housing portion to define a bearing surface for said blades.

References Cited by the Examiner UNITED STATES PATENTS 587,126 7/1897 McAdams 175213 X 682,939 9/1901 Ivens 175213 1,234,097 7/1917! Gilman 175-207 X 2,588,068 3/1952 Williams et al 175171 X 2,675,213 4/1954 Poole et a1 175-171 X 2,990,024 6/1961 Allsburg l-2l3 X 2,990,896 7/1961 Kandle 171 3,144,912 8/1964 Boehm et al 175-213 55 CHARLES E. OCONNELL, Primary Examiner.

R. E. FAVREAU, Assistant Examiner. 

1. A HOLE DIGGER COMPRISING: (A) A TUBULAR HOUSING HAVING AN ELONGATED BODY ADAPTED TO CONNECT WITH A SOURCE OF NEGATIVE PRESSURE, (B) A SHAFT EXTENDING LONGITUDINALLY OF SAID BODY, ONE END OF SAID SHAFT EXTENDING THROUGH SAID OPENING IN SAID HOUSING, (C) A BEARING FOR ROTATABLY JOURNALLING THE END OF THE SHAFT EXTENDING THROUGH SAID OPENING, (D) MEANS FOR RETAINING SAID BEARING TO SAID HOUSING, (E) MEANS FOR PROHIBITING LONGITUDINAL DISPLACEMENT OF SAID SHAFT WITHIN SAID HOUSING, (F) AND A CUTTER MEANS CONNECTED TO THE OTHER END OF SAID SHAFT, 